/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hive.ql.optimizer.calcite.rules;

import org.apache.calcite.plan.RelOptRuleCall;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.core.Aggregate;
import org.apache.calcite.rel.core.Aggregate.Group;
import org.apache.calcite.rel.rules.AggregateProjectPullUpConstantsRule;
import org.apache.hadoop.hive.ql.optimizer.calcite.HiveRelFactories;
import org.apache.hadoop.hive.ql.optimizer.calcite.reloperators.HiveAggregate;

public class HiveAggregatePullUpConstantsRule extends AggregateProjectPullUpConstantsRule {

  public static final HiveAggregatePullUpConstantsRule INSTANCE =
          new HiveAggregatePullUpConstantsRule();

  public HiveAggregatePullUpConstantsRule() {
    super(HiveAggregate.class, RelNode.class,
            HiveRelFactories.HIVE_BUILDER, "HiveAggregatePullUpConstantsRule");
  }

  @Override
  public boolean matches(RelOptRuleCall call) {
    final Aggregate aggregate = call.rel(0);
    // Rule cannot be applied if there are GroupingSets
    if (aggregate.getGroupType() != Group.SIMPLE) {
      return false;
    }
    return super.matches(call);
  }

}
